Prostaglandins and the gastrointestinal tract.
TL;DR: To assess fully whether PGs are normally involved in gut function it will be necessary to determine the site and mechanism of prostaglandin storage release action and metabolism and the rates of turnover during activity and at rest and to see how normal gut activity is affected by PGs by alteration of their tissue levels and rate of metabolism.
About: This article is published in Gastroenterology.The article was published on 1970-11-01 and is currently open access. It has received 255 citations till now. The article focuses on the topics: Prostaglandin a & Gastrointestinal tract.
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TL;DR: A large body of work pertaining to studies of eicosanoids in the gastrointestinal tract is distill to present a clear summary of this area of gastroenterology so that future research can be directed in a logical and productive manner.
434 citations
TL;DR: The involvement of prostaglandins and related compounds in mucosal protection, in ulcer healing, in diarrhea, and in gastrointestinal inflammation is reviewed, with particular reference to the growing body of human data.
356 citations
TL;DR: Results indicate that gastric motility may be an important factor in the pathogenetic mechanism of indomethacin-induced gastric lesions in rats, and a deficiency of endogenous PGs may be a prerequisite for later extension of the lesions.
Abstract: Effects of indomethacin on gastric motility and secretion, and levels of endogenous prostaglandins (PGs) were investigated in rats, in attempts to elucidate the factors involved in the pathogenesis of indomethacin-induced macroscopic gastric lesions. Subcutaneous administration of indomethacin had no effect on the gastric mucosa at doses of 1 and 5 mg/kg, but induced visible lesions dose dependently at over 10 mg/kg within 4 hr. At 25 mg/kg, there were apparent nonhemorrhagic lesions within 1 hr, and these lesions became hemorrhagic with time. Acid secretion was not affected by this agent at either dose level, but pepsin or acid-induced HCO3− secretion was significantly increased or decreased, respectively, at a dose less than 5 mg/kg, which did not induce any lesion. Gastric motility, however, was dose dependently increased after administration of indomethacin, and its effect was significant at 10 mg/kg or greater. Time-course changes in the motility were in parallel with those of the lesion formation. PGE2 and 6-keto PGF1α levels in the corpus mucosa were reduced around 80–90% for more than 4 hr from 30 min after administration of 5 mg/kg or more of indomethacin. When all the above changes caused by indomethacin were plotted for the various doses, a significant correlation (r=0.958, P<0.01) was found between the lesion index and the changes in motility, but not in other factors, including PG levels. These results indicate that gastric motility may be an important factor in the pathogenetic mechanism of indomethacin-induced gastric lesions in rats. A deficiency of endogenous PGs may be a prerequisite for later extension of the lesions.
178 citations
TL;DR: Junal, ileal, and colonic water and electrolyte transport was studied in Shigella flexneri 2a-infected monkeys to find out why shigellosis is both a small and large intestinal disease.
176 citations
References
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TL;DR: The liver and lungs provide an efficient protective mechanism to remove almost all the prostaglandin before it reaches the arterial circulation.
Abstract: Prostaglandins are released into the splenic venous blood when the spleen contracts Whatever the significance of this release, the liver and lungs provide an efficient protective mechanism to remove almost all the prostaglandin before it reaches the arterial circulation
842 citations
Journal Article•
TL;DR: The prostaglandins are a family of lipids, originally discovered over 30 years ago in human seminal fluid, which have since been found not only to have a wide variety of striking pharmacological actions, but also to be present in many if not all mammalian tissues.
Abstract: The prostaglandins are a family of lipids, originally discovered over 30 years ago in human seminal fluid, which have since been found not only to have a wide variety of striking pharmacological actions, but also to be present in many if not all mammalian tissues. They have an unusual chemical structure, being 20-carbon fatty acids derived enzymically from the essential fatty acids by cyclization and oxidation. Converting enzymes have been demonstrated in many tissues; they are especially active in the vesicular glands of the sheep, which are used for a practical method of biosynthesis.
The individual prostaglandins differ among themselves both qualitatively and quantitatively. Prostaglandins have a wide spectrum of biological action: They are smooth muscle stimulants, depressor peripheral vasodilators (except the PGFs which are pressor and venoconstrictor in dogs), and inhibitors of lipolysis, platelet aggregation and gastric secretion. In these areas, they are among the most potent compounds known, activity being present in some systems at concentrations of 0.01 ng/ml in vitro , and activity of 10 ng/kg in vivo . Prostaglandin formation and release is brought about by nerve activity, both central and peripheral. Their presence in biologically large concentrations in menstrual fluid and amniotic fluid at term is intriguing.
Physiological roles for these recently rediscovered compounds are yet to be established, but whenever substances are found in tissues which in very small doses can affect the function of these tissues, there is the possibility that they are regulators of physiological activity. Each effect of one or another prostaglandin suggests a corresponding physiological role, whether stimulatory or inhibitory, on such systems as smooth muscle, nerves, the circulation, and the reproductive organs. In the last named, roles in relation to fertilityand coitus and later possible action in relation to labor and postpartum uterine contraction have been proposed. Prostaglandins liberated by nerve stimulation, which then have actions opposite to that of the nerve stimulation, suggests a role as feed-back inhibitors. Thus, sympathetic nerve stimulation to adipose tissue induces both lipolysis and the release of antilipolytic prostaglandins, and vagal stimulation to the stomach, both secretion and the release of prostaglandins with powerful antisecretory actions. On the other hand, the ability of minute amounts of certain prostaglandins, inactive in their own right, to potentiate other agonists, suggests a more general role on ion transport or membrane function.
595 citations
TL;DR: Prostaglandins work to reduce blood pressure, and affect the heart beat, lipolysis, and the workings of the smooth musculature.
377 citations
TL;DR: Prostaglandin, a smooth muscle-stimulating depressor acidic lipid discovered int he human seminal plasma in 1935, is now used as a generic term for a family of closely related derivatives of prostanoic acid which are widely distributed in animal tissues.
Abstract: Prostaglandin, a smooth muscle-stimulating depressor acidic lipid discovered int he human seminal plasma in 1935, is now used as a generic term for a family of closely related derivatives of prosta...
363 citations